Man’s nature is that of a sinner. It is inescapable until glorification. Following the justification / sanctification / glorification model I think the Bible is clear on the requirements of salvation and the future state of the believer after death or rapture. It seems that sanctification is where we struggle. How is a Christian to live? If man is sinful should we struggle to escape sin and risk legalism or simply “be” and ask for forgiveness.
The New Testament clearly states that there are behavioral standards to which Christians should aspire. Every one of Paul’s letters contains some kind of admonition in that regard, and Peter, James and John are no different. Aspiring to these standards is meant to be an expression of gratitude for what’s already been given us. Paul called it “living up to what we’ve already attained” (Phil. 3:16) but some others have tried to turn these standards into another set of rules and added penalties for non-compliance.
Salvation is a free gift given on the basis of belief, not behavior, and brings eternal comfort. But sanctification brings true fellowship with God, opening the door to additional blessings, as long as our motives are right.
If we’re trying to live up to Biblical standards out of fear or a sense of duty, or for the sake of appearance, we’ve got the wrong motives and we’ll become the miserable wretch Paul described himself as being in Romans 7.
But if we do so purely out of our love for the Lord and because we want to please Him, that’s the right motive, and we’ll receive blessings beyond measure, both in this world and in the next. Same behavior, different motives, different outcome.
Of course we’ll fall short sometimes, but when we do we can confess and receive the Lord’s forgiveness, and it will be like it never happened (1 John 1:9).
So we don’t try to live a certain way because we’re under a law that says we have to. We try to live a certain way because we’ve been saved by the grace of God and we’re so grateful that we want to.